Difference Between Porpoises and Dolphins

However, porpoises tend to be shorter and chubbier than dolphins. A porpoise's snout is shorter and blunter than a dolphin's snout.

Dolphins and porpoises have differently-shaped teeth. While a dolphin's teeth are cone-shaped, a porpoise's teeth are flat and spade-shaped.

Porpoises have triangular dorsal fins (back fins) while dolphins have falcate (sickle-shaped) dorsal fins. (Some porpoises and some dolphins do not have dorsal fins.)

While dolphins make sounds that human beings can hear, the sounds that porpoises make are inaudible to humans.

In general, porpoises tend to be shyer around humans than dolphins.

Porpoise Species

There are 6 living species of porpoise:

the harbor porpoise (Phocoena phocoena)

the spectacled porpoise (Phocoena dioptrica)

Burmeister's porpoise (Phocoena spinipinnis)

Dall's porpoise (Phocoenoides dalli)

the finless porpoise (Neophocaena phocaenoides)

the vaquita (Phocoena sinus)

The vaquita is the smallest living cetacean on Earth. A vaquita can grow up to about 5 feet long and weigh up to about 110 pounds. Vaquitas live in the Gulf of California and are critically endangered.

"Vaquita" is Spanish for "little cow."

Classification

The porpoise family, Phocoenidae is part of the superfamily Delphinoidea, which also includes oceanic dolphins, the beluga whale (Delphinapterus leucas) and the narwhal (Monodon monoceros).